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In order to explore competitive bio-products to meet the requirements of the engineering structural member with high-strength, light-weight and low cost, bamboo bundle and wood laminated veneer lumbers (BWLVLs) with well-designed laminated structures have been regarded as potential candidate. Eight different assemble patterns of BWLVLs were designed and their mechanical performances with elastic range and ultimate bearing failure stage including the deflection, stress distribution, and stress transferring between adjacent layers were investigated using finite element simulations. The results showed that the finite element predicting model with a high accuracy could be used to optimize the design of laminated structures for bamboo bundle and wood veneer laminated composites. The relative error of the simulation results from the predicting model and the experimental results for different laminated composite panels was substantially less than 10%. The rank order for the VonMises stress of eight assemble BWLVLs were (7B) > (BBPPPBB) ≈ (BBPBPBB) > (BPBPBPB) > (BPPPPPB) ≈ (BPPBPPB) > (PBPBPBP) > (7P), (P) poplar, and (B) bamboo. The stress in laminated composites was transferred from poplar layers with low modulus to bamboo bundle layer with high elastic modulus. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the optimum processing parameters to manufacture wood-bamboo hybrid composites for railway sleepers. Wood particles and bamboo strips were used as reinforcing materials, and phenol formaldehyde resin was used as matrix. About 108 composite boards with resin contents of 8% to 15.5%, target densities of 0.55 to 1.05 g/cm3, hot-pressing time of 0.40 to 0.65 min/mm, and press temperatures of 165℃ to 175℃ were fabricated. The effect of manufacturing parameters on the properties of the sleepers was examined. Regression equations were developed to illustrate the relationships between processing parameters and the sleeper properties, i.e. modulus of rapture (MOR), modulus of elasticity (MOE), internal bonding (IB), and thickness swelling (TS). A nonlinear programming model was derived, from which the composite sleeper properties can be estimated. Given the manufacturing conditions (resin content, target composite density, press time, and press temperature), the composite sleeper properties can be estimated. Using the nonlinear programming model, the optimal MOR, MOE, IB, or TS could be obtained under certain practical constraints. When a resin content of 15.5%, target density of 0.8 g/cm3, hot-pressing time of 0.65 min/mm, and hot-pressing temperature of 170℃ were used, the optimal MOR value of 70.08 MPa was obtained under the conditions that MOE, IB, and TS be greater than the requirements of the standards. [ABSTRACT FROM PUBLISHER]